Thailand's election commission has called for upcoming polls to be delayed as street battles between security forces and protesters seeking to disrupt the ballot killed a police officer and injured nearly 100 people, dealing fresh blows to the beleaguered government.

Prime Minister Yingluck Shinawatra wants the February 2 elections to take place as scheduled, believing she would win handily and renew her mandate. The street violence adds to pressure on her to take a tougher line against the protesters, risking more chaos and possible intervention by the army.

The hours-long unrest took place outside a Bangkok sports stadium where election candidates were gathering to draw lots for their positions on ballots. Protesters threw rocks as they tried to break into the building to halt the process, while police fired tear gas and rubber bullets.

Police said protesters fired live bullets, one of which killed the officer.

Four election commissioners left the stadium by helicopter to escape the violence, some of the sharpest since a long-running dispute between Thailand's bitterly divided political factions flared anew two months ago, pitching the Southeast Asian country into fresh turmoil.

The protest movement regards the Yingluck administration as corrupt, illegitimate and a proxy for her brother, former Prime Minister Thaksin Shinawatra, who was toppled by a 2006 military coup. It is demanding that the elections be delayed until Yingluck leaves office and reforms are implemented.

The election commission said in a statement that it was urging the government to consider postponing the elections, citing the security situation. Commission head Somchai Srisutthiyakorn denied the body was "involving itself in politics" by urging a delay in the polls. "We have good intentions and want to see peace in this country," he told reporters.

Deputy Prime Minister Pongthep Thepkanchana said the government was unable to change the date of the polls.

"February 2, 2014, was set as the election date in the royal decree dissolving Parliament, and there is nothing within the constitution or the law that gives the government the authority to change this date," he said. He reiterated that the government was willing to discuss reforms with the protesters, but insisted that the elections must take place as scheduled.

According to the constitution, elections must be held 45 to 60 days from the date that Parliament is dissolved.

The anti-government protests began in late October, but today's violence was the first in nearly two weeks.

At least 96 people were injured from both sides as protesters armed with sling shots and wearing gas masks fought with police. An officer was struck by a bullet fired by the protesters, police said at a news conference. He died after being airlifted to a hospital, said police Colonel Anucha Romyanan.

Later in the day, protesters stormed a government building, vandalized cars and blocked a major road leading to the smaller of Bangkok's two airports.

Police have made no move to arrest the protest movement's ringleader, Suthep Thaugsuban, who is demanding the country be led by an unelected council until reforms can be implemented. The authorities have to tread carefully, as a crackdown would likely provoke greater violence and chaos. That could give the military, which has staged 11 successful coups in the past, a pretext to intervene again.

In a speech to supporters today, Suthep said he regretted the violence, but denied that protesters were responsible, instead blaming infiltrators or supporters of Yingluck. He vowed that the protesters would succeed in toppling the government.

Thailand has been wracked by political conflict since Thaksin was deposed seven years ago. The former prime minister now lives in self-imposed exile to avoid jail time for a corruption conviction, but still wields influence in the country.

Thaksin or his allies have won every election since 2001 thanks to strong support in the north and northeast of the country. His supporters say he is disliked by Bangkok's elite because he has shifted power away from the traditional ruling class, which has strong links to the royal family.

Yesterday, Yingluck announced a proposal for a national reform council to come up with a compromise to the crisis, but it was rejected by the protesters. The country's main opposition party, which is allied with the protesters, has announced it is boycotting the elections.

Yingluck led the country for two years relatively smoothly. But in October, her government tried to introduce an amnesty law that would have allowed Thaksin to return to the country as a free man, sparking the latest round of unrest.